Dexmedetomidine versus propofol for maintenance of anesthesia after sevoflurane induction in children undergoing MRI.

To compare clinical parameters and post-operative recovery when using dexmedetomidine versus propofol after induction with sevoflurane in children undergoing elective diagnostic MRI (magnetic resonance imaging).

Randomized controlled trial

This randomized controlled trial was carried out at the Department of Anesthesia, Combined Military Hospital Rawalpindi from Jan 2023-Jun 2023

Inclusion criteria: included all children aged 1-12 years of age presenting to the pre-anesthesia clinic for diagnostic MRI. Exclusion criteria: included patients <1 and >18 years, children with congenital heart disease or other congenital anomalies of major organs, children with known allergy to propofol or dexmedetomidine, children with major cardiac or respiratory disease, history of general anesthesia in the last 8 weeks, children with respiratory tract infections and children requiring intubation during the procedure for any indication required.

Inhalational induction with Sevoflurane 1.0 MAC (minimum alveolar concentration) was carried out and weight and age-appropriate i-gel (Laryngeal mask airway) was inserted to secure the airway. Maintenance of anesthesia was then carried out with IV Propofol and IV Dexmedetomidine in respective groups. Sevoflurane was then shut off and maintenance doses of both drugs were started. Patients in Group P (IV Propofol) received a maintenance infusion of 100 mcg/kg/min whereas patients in Group D (IV Dexmedetomidine) received a dose of 1 mcg/kg/hour titrated in an infusion pump till the time of completion of the procedure.

heart rate, mean arterial pressure, and respiratory rate recorded every 5 minutes during the maintenance of anesthesia till the end of the procedure.

. The patients were randomized into two groups of 70 patients each. After confirming nil per oral status in the recovery room of the MRI suite on the day of the procedure, an informed written consent was taken from the next of kin and they were explained about the parameters of the study protocol. Before going into the MRI suite, age, weight, and gender were recorded by a resident anesthetist unaware of the study protocol. Basic vital monitoring including blood pressure, heart rate, saturation, and electrocardiogram was attached. Pre-oxygenation was done with a good seal and appropriately sized facemask and continued till end-tidal O2 levels on the anesthesia machine were >90%. Inhalational induction with Sevoflurane 1.0 MAC (minimum alveolar concentration) was then carried out and weight and age-appropriate i-gel (Laryngeal mask airway) was inserted to secure the airway. Maintenance of anesthesia was then carried out with IV Propofol and IV Dexmedetomidine in respective groups. Sevoflurane was then shut off and maintenance doses of both drugs were started. Patients in Group P (IV Propofol) received a maintenance infusion of 100 mcg/kg/min whereas patients in Group D (IV Dexmedetomidine) received a dose of 1 mcg/kg/hour titrated in an infusion pump till the time of completion of the procedure. The infusion pumps were marked as X and Y and prepared by the consultant on duty to ensure blinding and parameters studies were recorded on a proforma given to the resident anesthetist on duty in the suite unaware of the study protocol or the drug used. Per-operative bradycardia (HR<80 and <60 according to respective age) was managed with IV atropine 0.02 mg/kg and hypotension (MAP <60) was managed with IV phenylephrine 10 mcg bolus12.